Tubular inserting device with variable rigidity

ABSTRACT

The inserting means comprises a flexible insertion part (14) adapted to be pushed into an object to be examined, especially the human colon (60) and including, between an inner wall (16) and an outer wall (18), an intermediate space (20) sealed towards the outside. The outer wall (18) is formed by a flexible hose which, however, cannot be inflated like a balloon by the fluid in the intermediate space (20). The inner wall (16) of the insertion part (14) likewise is formed by a hose; the latter is deformable radially inwardly by fluid introduced into the intermediate space (20) and can be caused to lie against the outer wall (18) by evacuation of the intermediate space (20). The insertion part (14) can be rendered rigid in any desired position by evacuating the intermediate space (20). It is easy to insert the corresponding instrument, e.g. the colonoscope into the object to be examined through the insertion part (14) thus fixed. The insertion part (14) becomes flexible again when the intermediate space (20) is filled with fluid, such as air.

BACKGROUND OF THE INVENTION

The invention relates to an inserting means for tubular, fiberopticinstruments, especially colonoscopes, gastroscopes, and the like,comprising a grip part and a flexible insertion part adapted to bepushed into an object to be examined, especially the human colon andincluding, between an inner wall and an outer wall, at least oneintermediate space which is sealed outwardly and into which a fluid canbe introduced. The outer wall of the insertion part is formed by aflexible hose which, however, is not inflatable like a balloon by thefluid in the intermediate space. The inner wall of the insertion partlikewise is formed by a hose, and The intermediate space containssupport elements through which the inner wall and the outer wall aremutually supported when the pressure in the intermediate space fails toreach a predetermined value.

An inserting means of this kind is known from U.S. Pat. No. 4,815,450.There the intermediate space contains ball shaped support elementsbetween the inner and outer walls of the insertion part which elementsare freely disposed and therefore movable in the intermediate space. Asa consequence, the support elements may become shifted in theintermediate space and consequently do not always reliably fulfill theirtask of stiffening the insertion part when there is a vacuum in theintermediate space. The user therefore cannot rely on the insertingmeans keeping a particular desired configuration during a particularmanipulation of a colonoscope or the like.

As is known, for example, from U.S. Pat. No. 4,696,544, there are fieldsof application for tubular fiberoptic instruments outside of the medicalfield, too, such as for examining pipelines, vessels, and machine parts.The term "object to be examined" is to be understood accordingly in thecontext of the present invention.

For inserting colonoscopes, also inserting means are being used whichhave a one-piece slip tube which is of great flexural stiffness ascompared to the corresponding colonoscope and permits only relativelyminor elastic bending. The inner diameter of such a slip tube for acolonoscope having an outer diameter of 15 mm, for instance, is barely16 mm so that the colonoscope can be pushed through easily any time. Theouter diameter of the slip tube is 19 mm, for example. The insertionpart is 40 cm long. The length of the associated colonoscope usually isbetween 130 and 180 cm. A distal end portion, approximately 10 cm long,of the colonoscope usually can be moved in four directions (up/down andleft/right) by means of setting wheels supported at the proximal end.

The physician performing an examination or treatment pushes thecolonoscope from the anus into the colon. The colonoscope must beadvanced up to the cecum in order to permit full examination of thecolon. In doing that, the direction of movement of the colonoscope canbe determined by its movable distal end portion. However, at the bendsof the colon, namely at the sigmoid and especially at the two colonflexures, problems regularly occur, including the risk of injury, painto the patient, and cramp-like contractions of the colon, even up to theimpossibility of continuing the examination. These problems are relatedto the fact that the colon is soft and fixed only relatively little inthe abdomen. After a deflection, the principal direction of the force bywhich the colonoscope is advanced no longer is towards the distal end ofthe colonoscope but instead towards the readily yielding wall of thecolon, a fact which is unpleasant for the patient. Therefore, the cecumcannot be reached in about 10 to 15% of all cases.

These difficulties can be overcome only in part by the customaryinserting means since they are suitable for guiding the colonoscope onlythrough the rectum and, at best, the sigmoid and the colon descendens.Yet the problems described continue to exist at the left colon flexure,at the latest. Moreover, many patients already find it unpleasant thatthe sigmoid is forced into an almost rectilinear shape by the slip tubesince the configuration of the slip tube is not variable at random. Dueto the great stiffness of the slip tube there is a risk of perforatingthe colon if the slip tube is handled carelessly.

A mechanical-pneumatical manipulation system for colonoscopes is knownfrom DE 36 05 169 A1 where an inserting means is intended to make iteasier for the physician and the patient to introduce a colonoscope.This inserting means, too, comprises a flexible slip tube into which thecolonoscope can be slipped. A balloon or group of balloons of highlyflexible material is arranged on the slip tube. In vented condition theballoon or group of balloons lies in close contact with the slip tube;in inflated condition the balloon or group of balloons is to findsupport in the surroundings, i.e. on the intestinal wall, and the shaftof the colonoscope is to be movable forwardly or backwardly with the aidof the mechanics. A second group of balloons firmly mounted on thecolonoscope shaft are vented when the colonoscope is to be displacedwith respect to the slip tube which is supported in the vicinity andthey are inflated when the slip tube is to be displaced together withits balloon or group of balloons. The slip tube includes longitudinalpassages one of which is intended to house pressure and vacuum conduitsand another one to receive a mechanical push-pull system.

This inserting means with an inflatable balloon or a group of suchballoons arranged at the outside cannot very much ease the insertion ofa colonoscope into the human intestine because the intestine reacts inthe same manner by spastic and painful contractions to every extension,regardless of whether it is caused by an unprotected colonoscope or byone or more blown up balloons. Such contractions also occur distally ofthe colonoscope and make it difficult to push it on. The known insertingmeans is not suited for non-medical objects of examination, such asparts of machinery which may have sharp-edged inner contours because aballoon assembly on the flexible slip tube is susceptible of damage.

The same applies mutatis mutandis to a device known from DE 28 23 025 C2for transferring a colonoscope where the distal end of the colonoscopeis connected by a thin, overturned hose to the distal end of a conicaltube adapted to be introduced into the human anal ring. A housingenclosing the colonoscope and provided with a connecting socket can bescrewed on to the proximal end of the tube. When a pressure medium isintroduced through the connecting socket a portion of the hose locatedbetween the two hose ends is pushed into the large intestine while, atthe same time, it turns inside out, pulling along the colonoscope. Thelatter thus is to move into the intestine by being pulled rather thanpushed. As the hose advances, its interior is to turn inside outprogressively so that then it will form an outer hose portion which doesnot move with respect to the mucous membrane of the intestine. However,that may also cause painful spastic intestinal contractions. Even if itis possible with this known device to advance a colonoscope far enough,especially all the way to the cecum, it is still not possible to leavethe hose in the intestine and use it as an aid for the renewed insertionof the colonoscope if the latter has been pulled out preliminarily, forexample to remove a larger polyp. The hose which can be overturned andconsequently must be thin is not suitable for technical applicationsbecause it can tear easily at sharp edges and protrusions of the objectunder examination.

SUMMARY OF THE INVENTION

It is the object of the invention to devise an inserting means fortubular fiberoptic instruments, especially colonoscopes, gastroscopes,and the like in such a manner that it substantially facilitates thecomplete and multiple insertion, if required. of such an instrument allthe way to the end of the object to be examined and, in case of medicalexaminations, makes this more tolerable for the patient and easier forthe physician.

Starting from an inserting means of the kind described initially, thisobject is met, in accordance with the invention, in that some of thesupport elements are firmly arranged at the outside of the inner walland the remainder of the support elements are firmly arranged at theinside of the outer wall.

The support elements may be warts, helices, fins, and the like. The firmor fixed arrangement of the support elements can result from one-piecemanufacture of the support elements and the associated inner or outerwall, or from gluing, fusing, or vulcanizing separately made supportelements to the walls. The inner and outer walls together present aninsertion part which can be rendered rigid in any desired bent shape,e.g. adapted to the sigmoid and even to the two colon flexures, byevacuation of the intermediate space to such a degree that the supportelements of the inner wall abut against those of the outer wall. Afiberoptic instrument, especially a colonoscope can be introduced withrelative ease through the insertion part thus deformed and fixed. Iffluid is again introduced into the intermediate space the insertion partregains its original flexibility.

The inner wall preferably is deformable radially inwardly by fluidintroduced into the intermediate space, thereby coming to lie against asheath surface of a fiberoptic instrument, especially a colonoscopepassed through the inserting means. The inner wall of the insertion partthus can be pressed firmly against an instrument, especially acolonoscope passed through the inserting means by introducing apressurized fluid, such as compressed air into the intermediate spacewithout blowing up the outer wall. In this state the inserting meansstill is flexible and can be advanced together with the fiberopticinstrument due to its temporary fixed connection to the same. Thus it isno problem to reach the end of the area to be examined, for example thececum by alternatingly pushing forward the instrument alone and theinstrument together with the inserting means.

Particularly solid interlocking and thus high bending resistance of theevacuated insertion part results if the support elements which arearranged at the outside of the inner wall each engage in a gap betweensupport elements provided at the inside of the outer wall.

The intermediate space can be subdivided into a plurality of chambersadapted to be evacuated and pressurized, if needed, in common orseparately. Such chambers may be separated from each other, forinstance, by welding seams or other seams interconnecting the inner andouter walls in the manner of quilted seams. The chambers may extendrectilinearly or helically along the insertion part. The inner and outerwalls can form uniform wall sections between the chambers.

In a preferred embodiment of the invention the support elements whichare firmly arranged at the inner wall of the insertion part are ofsleeve-like design and each engage between two adjacent sleeve-likesupport elements which are firmly arranged at the outer wall of theinsertion part. With this embodiment the insertion part can be stiffenedespecially effectively by evacuating the space intermediate its innerand outer walls.

The embodiment described above may be developed further in that thesupport elements arranged at the inner wall are designed to be radiallyexpansible and compressible by slots formed over part of their axiallength. Due to this measure the slotted support elements arranged at theinner wall snugly engage the support elements of the outer wall uponevacuation. Such slots further make it possible to bend the insertionpart around particularly narrow radii.

On the other hand, it is advantageous if the support elements arrangedat the outer wall comprise a non-extensible annular bead at both endswhich covers the slots of the two adjacent support elements over part oftheir axial extension only so that all parts of the intermediate spaceare interconnected through at least part of the slots, no matter whatthe position of the insertion part. Such annular beads have theadditional advantage of counteracting any tendency of the outer wall tobecome inflated when positive pressure prevails in the intermediatespace between the inner and outer walls.

The stiffening of the insertion part, with the intermediate spaceevacuated, can be enhanced by providing the support elements arranged atthe inner wall with an external corrugation and the support elementsarranged at the outer wall with a corresponding internal corrugation.The corrugations which thus are located radially opposite each otherbecome interlocked when the intermediate space is evacuated so that theinsertion part is fixed in form lock in the position it had just beforeevacuation of the intermediate space.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will be described in greater detail belowwith reference to diagrammatic drawings, in which:

FIG. 1 is an overall view of an inserting means according to theinvention comprising a insertion part and associated equipment;

FIG. 2 shows the cross section II--II through the insertion part ininflated state and on greatly enlarged scale;

FIGS. 3a to f show six consecutive manipulations of a colonoscope withan inserting means;

FIG. 4 shows a second embodiment of an insertion part according to theinvention in cross section IV--IV of FIG. 5, in inflated state;

FIG. 5 shows the longitudinal section V--V of FIG. 4 still moreenlarged; and

FIG. 6 shows the cross section VI--VI of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The main components of the inserting means 10 illustrated in FIGS. 1 and2 are a grip part 12 and an insertion part 14. The insertion part 14comprises an inner wall 16, an outer wall 18, an annular intermediatespace 20 formed between said walls, a distal end portion 22, and finallya distal guide ring 24. At the grip part 12 and at the distal endportion 22 the inner wall 16 is connected tightly to the outer wall 18whereby the intermediate space 20 is sealed.

According to FIG. 1 the grip part 12 substantially consists of an innersleeve 26 to which the inner wall 16 is tigthly secured and an outersleeve 28 to which the outer wall 18 is tightly secured. The inner wall16 and the outer wall 18, for instance, may be vulcanized, glued, and/ortightly clamped to the respective sleeve 26 or 28. The two sleeves 26and 28 are tightly connected to each other at their proximal endportions, for example by being threaded together.

A connection 30 for supply and withdrawal of fluid into and out of theintermediate space 20 is located at the outer sleeve 28 or in aconnecting area between the outer sleeve 28 and the inner sleeve 26. Aslide ring sealing each is suitably arranged at the inside of the innersleeve 26 of the grip part 12 and at the distal end portion 22 of theinsertion part 14 to provide sealing against the associated fiberopticinstrument. An additional suction and/or rinsing conduit may open intothe interior of the inner sleeve 26 in order that air or secretion froma body organ under examination can be sucked off or a rinsing liquid beintroduced through the inserting means.

The inner wall 16 and the outer wall 18 each are formed of a tubularfilm of pliable plastic material which is physically tolerable. In theembodiment illustrated in FIG. 2 the inner wall 16 is less thick thanthe outer wall 18 and consequently can be deformed radially inwardlywith ease when positive pressure is generated inside the intermediatespace 20; the outer wall 18 on the other hand is so solid and reinforcedwith fibers, if desired, that it does not become inflated by a pressureprevailing in the intermediate space 20 which already produces quitesome deformation of the inner wall 16.

According to FIG. 2, support elements 32 are disposed evenly distributedat the outside of the inner wall 16; gaps 34 are left between them. Incorresponding manner support elements 36 and gaps 38 are arranged at theinside of the outer wall 18 in such manner that each support element 32is located radially opposite a gap 38 and each support element 36 islocated radially opposite a gap 34. As long as ambient pressure prevailsin the intermediate space 20 the support elements 32 and 36 touch eachother only lightly or not at all. This condition is represented in FIG.2. However, each support element 32 enters into a gap 38 and eachsupport element 36 enters into a gap 34 as the intermediate space 20 isevacuated more or less. Hereby the insertion part 14 is rendered rigidin any desired configuration which it had adopted prior to theevacuation.

To use the inserting means according to the invention, the connection 30is hooked up via a hose 40 to a control apparatus 42 of conventionaltype which, for example, connects the hose selectively to a compressedair conduit 46 or a vacuum conduit 48 by actuation of a rocker-typeswitch 44. A commercially available colonoscope 50 is inserted, distalend 52 first, into the proximal end of the guide tube 10 and pushedthrough the grip part 12 as well as the insertion part 14.

The further manipulation of the inserting means 10 and the colonoscope50 takes place at the patient and is illustrated in FIGS. 3a to 3f. Ineach case the joint presentation of the insertion part 14 and thecolonoscope 50 as a thick line means that air (or another fluid) hasbeen fed under pressure into the intermediate space 20, and thereby theinner wall 16 has been brought into close engagement with thecolonoscope 50; the insertion part 14 then is just as flexible as thecolonoscope 50. The presentation of the insertion part 14 as a pair ofthin lines distinguishable from the colonoscope 50, on the other hand,means that negative pressure prevails in the insertion part 14 at whichthe inner wall 16 releases the colonoscope 50 for relative shiftingmovements and is itself firmly engaged with the outer wall 18 so thatthe insertion part 14 is stiffened.

According to FIG. 3a the colonoscope 50, together with the pliableinsertion part 14 firmly in contact with it, is pushed into the colon60, beginning from the anus 62, through the rectum 64 up to thetransition from the sigmoid 66 to the colon descendens 68. The insertionpart 14 is rendered rigid in this position by evacuating itsintermediate space 20.

According to FIG. 3b the endoscope 50 is advanced up to the left colonflexure 70 through the inserting means 10 which has the rigidifiedinsertion part 14.

According to FIG. 3c the stiffening of the insertion part 14 iscancelled by introducing compressed air into its intermediate space 20;the sigmoid 66 is straightened somewhat, and the insertion part 14, too,is pushed on to the left colon flexure 70.

In the position according to FIG. 3d the insertion part 14 is rigidifiedonce more and the colonoscope 50 is pushed through the left colonflexure 70.

According to FIG. 3e the stiffening of the insertion part 14 has beencancelled again; the insertion part 14 now is pushed up beyond the leftcolon flexure 70 and then rendered rigid once more; subsequently theendoscope 50 is advanced up to the right colon flexure 74 and beyond.

According to FIG. 3f the stiffening of the insertion part 14 is given upagain; the insertion part 14, too, is pushed up beyond the right colonflexure 74 and then stiffened again so that the colonoscope 50 now canbe advanced further all the way into the cecum 78.

In each of the positions described and in all intermediate positions ofthe inserting means 10 the colonoscope 50 can be pulled out completely,for example in order to carry a tumor to the outside which has beenremoved by a sling but cannot be passed through the colonoscope 50.Subsequently the colonoscope 50 can be reinserted through the insertingmeans 10 which remained in stiff condition inside the colon 60, andfurther tumors can be excised and moved to the outside, if necessary.

The preferred embodiment of the invention shown in FIGS. 4 to 6 hasring- or sleeve-like support elements 32 arranged at the outside of theinner wall 16 which are each fastened to the inner wall 16 by an annularweld or glue attachment 82 centrally located on each element. Eachsupport element 32 includes axis parallel slots 84 starting from bothits face ends and each extending for almost half the axial width of thesupport element 32. The slots 84 are of such width that the annularsupport elements 32 can be highly compressed and also widened in radialdirection in their end regions.

Ring- or sleeve-like support elements 36 are arranged at the inside ofthe outer wall 18 and likewise each fastened to the outer wall 18 by anannular weld or glue attachment centrally located on each element. Eachsupport element 32 enters axially between two adjacent support elements36; in corresponding manner each support element 36 extends over the twoadjacent support elements 32 for part of their axial length, e.g. aboutone third thereof. The support elements 36 are not slotted but insteadprovided at each end with an annular bead 88 which is only slightlyextensible or not at all.

The support elements 32 each have a spherical outer face provided withcorrugations 90; the support elements 36 are of complementary sphericalshape at the inside of their annular beads 88 and provided withcorresponding corrugations 92. When the intermediate space 20 againdefined between the inner wall 16 and the outer wall 18 is evacuated thecorrugations 90 and 92 of overlapping support elements 32 and 36 engageeach other, thus fixing the support elements in the position they heldat the beginning of the evacuating process. The slots 84 formlongitudinal channels which make sure that the intermediate space 20between the inner 16 and outer walls 18 can be evacuated without anydifficulty over the full length of the insertion part 14. Due to theinterlocking corrugations 90 and 92 the insertion part 14 is given astiffness, in the evacuated state of its intermediate space 20, which ismany degrees higher than the stiffness, which is very low as such, ofthe inner wall 16 and the outer wall 18. This rigidness can be achievedwith the insertion part 14 in any desired bent configuration.

What is claimed is:
 1. An inserting device (10) tubular fiberopticinstruments comprisinga flexible insertion part (14) adapted to bepushed into an object to be examined, includingan inner wall (16) beingformed by a hose that is radially expandable, an outer wall (18) beingformed by a flexible hose that is not radially expandable, said innerwall (16) and outer wall (18) defining at least one sealed intermediatespace (20) into which fluid can be introduced, and support elements (32,36) contained within said intermediate space (20) and being fixedlyarranged on the outside of the inner wall (16) and on the inside of theouter wall (18) to mutually cooperate for adding rigidity to theinserting device when the pressure in the intermediate space (20) isbelow ambient pressure.
 2. The inserting device as claimed in claim 1,characterized in that the support elements (32) which are arranged atthe outside of the inner wall (16) each engage in a gap (38) formedbetween support elements (36) at the inside of the outer wall (18). 3.The inserting device as claimed in claim 1, characterized in that thesupport elements (32, 36) extend around the circumference of the outsideof the inner wall (16) and around the circumference of the inside of theouter wall (18) as continuous reinforcements of the inner (16) and outerwalls (18).
 4. The inserting device as claimed in claim 3, characterizedin that the support elements (32) which are fixedly arranged at theinner wall (16) of the insertion part (14) are formed as sleeves, eachengaging two adjacent sleeves that form support elements (36) which arefirmly arranged at the outer wall (18) of the insertion part (14). 5.The inserting device as claimed in claim 4, characterized in that thesupport elements (32) arranged at the inner wall (16) are designed to beradially expansible and compressible by slots (84) over part of theiraxial extension.
 6. An inserting device (10) for tubular fiberopticinstruments comprisinga flexible insertion part (14) adapted to bepushed into an object to be examined, including an inner wall (16) beingformed by a hose that is radially expandable, an outer wall (18) beingformed by a flexible hose that is not radially expandable, said innerwall (16) and outer wall (18) defining at least one sealed intermediatespace (20) into which fluid can be introduced, and support elements (32,36) contained within said intermediate space (20) and being fixedlyarranged on the outside of the inner wall (16) and on the inside of theouter wall (18) to mutually cooperate for adding rigidity to theinserting device when the pressure in the intermediate space (20) isbelow ambient pressure, wherein the support elements (32, 36) extendaround the circumference of the outside of the inner wall (16) andaround the circumference of the inside of the outer wall (18) ascontinuous reinforcements of the inner and outer walls, and wherein thesupport elements (32) which are fixedly arranged at the inner wall (16)are formed as sleeves, each engaging two adjacent sleeves that formsupport elements (36) which are fixedly arranged at the outer wall (18),and wherein the support elements (32) arranged at the inner wall aredesigned to be radially expansible and compressible by slots (84) overpart of their axial extension, and wherein the support elements (36)arranged at the outer wall (18) comprise a non-extensible annular bead(88) each at both ends which covers only part of the axial extension ofthe slots (84) of the two adjacent support elements (36) so that allparts of the intermediate space (20) communicate with each other throughat least part of the slots (84).
 7. The inserting device as claimed inclaim 1, characterized in that the support elements (32) arranged at theinner wall (16) are formed with corrugations (90) facing the outside,and that the support elements (36) arranged at the outer wall are formedwith corresponding corrugations facing the inside.
 8. The insertingdevice as claimed in claim 1, characterized in that the support elements(32, 36) are made integral with the respective inner (16) and outerwalls (18).
 9. The inserting device as claimed in claim 1, characterizedin that the inner wall (16) is deformable radially inwardly by fluidintroduced into the intermediate space (20), thereby being adapted toengage a sheath surface of a fiberoptic instrument, especially acolonoscope (50) passed through the inserting device (10).
 10. Theinserting device as claimed in claim 2, characterized in that thesupport elements (32, 36) extend around the circumferences as continuousreinforcements of the inner (16) and outer walls (18), respectively.